An electric automobile, in which a battery unit having a service plug is mounted beneath a floor panel, is disclosed in Japanese Patent Application Laid-Open (JP-A) No. 2009-083601. The service plug is structured so as to be able to electrically cut-off the electrical circuits of the battery module by being operated manually. Further, a boot mounting hole for operating the service plug is formed, and a cap member that closes this boot mounting hole is mounted by bolts. Further, an erroneous assembly preventing convex portion that is shaped so as to be convex downward is formed at the central portion of this cap member.
The erroneous assembly preventing convex portion at the central portion of this cap member contributes to improving the strength of the cap member. However, the top surface of the cap member is recessed due to the erroneous assembly preventing convex portion being formed. Further, due to water collecting in this recess over a long period of time, the cap member deteriorates and is easily damaged. Accordingly, there is room for improvement with regard to this point.
Note that related techniques are disclosed in JP-A No. 2013-107542 and JP-A No. 2013-112225.